<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>percent</title>
  </head>
  <body bgcolor="#FFFFFF">
    <center>Scilab Function</center>
    <div align="right">Last update : April 1993</div>
    <p>
      <b>percent</b> -  (%) special character</p>
    <h3>
      <font color="blue">Description</font>
    </h3>
    <p>
    Some predefined variables names begin with <tt>
        <b>%</b>
      </tt>, such as
    <tt>
        <b>%i</b>
      </tt> (for <tt>
        <b>sqrt(-1)</b>
      </tt>), <tt>
        <b>%inf</b>
      </tt> (for <tt>
        <b>Infinity</b>
      </tt>), <tt>
        <b>%pi</b>
      </tt> (for <tt>
        <b>3.14...</b>
      </tt>),
    <tt>
        <b>%T</b>
      </tt> (for the boolean constant <tt>
        <b>"true"</b>
      </tt>),...</p>
    <p>
    In addition, functions whose names begin with <tt>
        <b>%</b>
      </tt> are special : 
    they are used for primitives and operators overloading (see <tt>
        <b>overloading</b>
      </tt>).</p>
    <p>
    For example the function <tt>
        <b>%rmr</b>
      </tt> performs the multiplication (<tt>
        <b>m</b>
      </tt>)
    operation <tt>
        <b>x*y</b>
      </tt> for <tt>
        <b>x</b>
      </tt> and <tt>
        <b>y</b>
      </tt> rational matrices (<tt>
        <b>r</b>
      </tt>).
    The coding conventions are given by the readme file in 
    directory <tt>
        <b>SCIDIR/macros/percent</b>
      </tt>.</p>
    <h3>
      <font color="blue">Examples</font>
    </h3>
    <pre>

x1=tlist('x',1,2);
x2=tlist('x',2,3);
deff('x=%xmx(x1,x2)','x=list(''x'',x1(2)*x2(2),x2(3)*x2(3))');
x1*x2
 
  </pre>
    <h3>
      <font color="blue">See Also</font>
    </h3>
    <p>
      <a href="overloading.htm">
        <tt>
          <b>overloading</b>
        </tt>
      </a>,&nbsp;&nbsp;</p>
  </body>
</html>
